Xeviat
Dungeon Mistress, she/her
I had a whole essay I wrote up on this once. The Warlock is very nearly a 4E character, with at-wills, encounters, dailies, and utilities, just built out of order.The issue with comparing to 4e is 4e's issue was more presentation than mechanics. A lot of the ideas of 4e were very good, but they were presented so....clinically....little power cards on white sheets that really did make you think of a card or video game. 4e I think had a bigger PR problem than a mechanics one. Doesn't mean it wasn't a big problem, I mean the fact that 4e's handbook reads like a textbook and 5e's reads like a mystical tome is a major improvement on the experience.
Now I think one thing 4e did miss was the idea of repeatable powers. 4e's slots were mainly at will, once per encounter, once per day. And once that power was used, it was used. I think the notion of "Prof mod per day or even per fight" is much smoother. I think people can get behind the idea they can't do a special something in a fight every round all the time, but there is a big difference between one time and never see it again in 5 rounds, vs using something 2 or 3 times.
Basically, my question here is how would people react if the bard, cleric, druid, paladin, ranger, sorcerer, and wizard were rebuilt on the warlock chassis instead of the warlock being built on its own. No one decries sameyness when those seven classes have the same skeleton; I'd be real curious to see how the game progressed differently.